Overview
ISO/TR 24188:2022 is a Technical Report from ISO/TC 92 that provides a global overview of approaches to standardization for large outdoor fires and the built environment. The report reviews testing methodologies related to building vulnerabilities from large outdoor fire exposures (including WUI fires, urban/post‑disaster fires, tsunami‑ or volcano‑generated fires and informal settlement fires) and summarizes land‑use management practices. It clarifies that some test methods were originally developed for internal building fires and have been extrapolated to external fire exposures. (Note: evacuation strategies are not addressed.)
Key Topics and Technical Coverage
- Ignition scenarios: clear explanation of the three primary ignition pathways - direct flame contact, thermal radiation, and firebrands/embers - and how combinations of these drive large outdoor fire behavior.
- Regulatory principles and strategies: comparative review of national and regional approaches (examples include Japan, California building code, NFPA 1144, IWUIC, France, Australia).
- Building element test approaches: summarized methods and considerations for high‑risk components such as:
- Roofing assemblies (performance tests and national approaches)
- Exterior walls and facades (indoor vs outdoor test extrapolations)
- Other elements - vents, decks, eaves, windows
- Reaction‑to‑fire provisions: discussions of how reaction‑to‑fire criteria are applied in different jurisdictions.
- Annex and references: informative Annex A gives a precise description of roof performance tests defined in CEN/TS 1187; comprehensive bibliography and terminology (e.g., WUI, firebrand, spot fire).
Practical Applications and Who Uses It
ISO/TR 24188:2022 is intended as a reference for practitioners and stakeholders working to reduce structure ignition and damage from large outdoor fires:
- Standards developers and regulators - to align or develop building codes and land‑use rules for WUI and other large fire exposures.
- Fire safety engineers and researchers - to compare test methodologies and identify knowledge gaps.
- Architects and building designers - to inform material and assembly selection for exterior assemblies (roofs, walls, windows).
- Manufacturers of cladding, roofing and facade systems - to understand test expectations and performance contexts.
- Urban planners and land‑use authorities - for integrating vegetation management and community‑scale mitigation measures.
- Emergency managers and policy makers - to support risk assessment and mitigation planning.
Related Standards (if applicable)
- NFPA 1144 - Standard for Reducing Structure Ignition Hazards from Wildland Fire (referenced in the report)
- International Wildland‑Urban Interface Code (IWUIC)
- California State Building Code provisions (discussed)
- CEN/TS 1187 - roof performance tests (described in Annex A)
- ISO/TC 92 publications and ISO/TS materials on wildland fire terminology
Keywords: ISO/TR 24188:2022, large outdoor fires, WUI, firebrands, thermal radiation, building vulnerabilities, testing methodologies, land use management, roofing assemblies, exterior facades.